This invention relates generally to apparatus and methods for controlling the air to gas ratio of fuel being supplied to gas (gaseous fueled) engines. More specifically, this invention relates to an improved apparatus and method for controlling the air to gas ratio of fuel being supplied to a gas engine wherein the regulator controlling the gas flow to the carburetor is actuated by a pressure which varies between the pressure in the intake to the carburetor and the pressure in the intake manifold of the engine.
Carburated gas engines normally use at least one pressure regulator in the gas line to produce a controlled pressure at the carburetor. The conventional regulator has a diaphragm that produces a force balance between air pressure plus an adjustable spring force on one side and the regulated gas pressure on the other. If the air pressure plus the adjustable spring force exceeds the regulated gas pressure, the valve open and the gas pressure increases. If the regulated gas pressure exceeds the air pressure plus the adjustable spring force, the valve closes and the gas pressure decreases.
The aforedescribed regulator provides a regulated pressure of gas to the carburetor in which the air fuel ratio is presumably controlled. Relatively small changes in ambient conditions, however can cause the air fuel ratio to change and hence cause the engine to operate less efficiently. For example, changes in ambient temperature, humidity, engine temperature and fuel BTU content can all affect the efficiency.
At the present time, high operating efficiencies for the engine are very desirable and the high operating efficiencies are not available with the regulators utilized previously. Accordingly, it is an object of this invention to provide a simple method and apparatus for controlling the air to gas ratio in gas engines that utilize the commercially available regulators, but, provide better efficiencies than in engines operating with standard regulator systems.